As the Thanksgiving and other end of year holidays come upon us, more wine bottles will be popped and served, both at home as well as dining out in restaurants. That means the odds of perhaps buying or being served a tainted bottle can increase.

There is a reason why that “wine stewart” always pours a sample of wine for someone at your table to taste before serving. I’m certain that a very small percentage of wine drinkers out there have ever had to send or take a bottle back, or even know what to look for, and why a bottle can be bad. I’m hoping that this post can help you in the situation, if it ever happens to you.

There are a reasons that a wine “turns” and is not drinkable, with some the fault of the winery who bottled the wine, and sometimes it’s the fault of the person who cared for that bottle after it left its mother winery. In the above instance, a “corked” bottle is one where the cork was contaminated before being placed in the neck of that bottle. Organisms grow inside, and actually eat at the cork, which is why it broke up when you tried to open it. With red wines, especially ones that have aged a while, you will know quickly that there is something wrong. That’s why when dining out, as well as in your home if you are serving properly, you or someone with knowledge, tastes the wine before it is served. Keep in mind that smelling a cork is not going to tell you the wine is bad. Your swirl, sniff and taste, if you even get to the taste part will tell you.

A wine can turn bad because it has maderized, where it has been exposed to excessive heat while stored. Evident usually by the cork appearing to be pushed out a bit, and tasting heavy like a Madeira wine. Another possibility is that some residual yeast remained in the wine, and “re-fermented” in the bottle. Your fine red wine will pour with a fizz like a sparkling wine. And then there is a wine that has “oxidized” where somehow the wine has gotten exposed to oxygen. You won’t notice any odor coming from this wine, but rather should notice that the color is dull, especially with whites that may appear brownish. The taste is flat, lifeless with no excitement, with the exception of tasting like vinegar.

Perhaps you have either ordered a fine bottle of wine from wine list, or asked the restaurant Sommelier for a recommendation, and asked for a bottle. In most cases, when that bottle arrives, you are asked to inspect the bottle, its label, and if acceptable the bottle is opened for you. The cork is placed in front of you for examination, but really now, the proof is in the pudding, not the bowl, so let’s give it a swirl, sniff and taste. You immediately realize that one of the problems mentioned above is at hand here and the wine is bad. You inform the waiter or wine Stewart, and they will follow the protocol of the restaurant. They may offer to replace it with another bottle of this wine, or allow you to purchase a different bottle.

Another scenario could be the restaurant owner or wine “expert” would pour a glass and taste it themselves to confirm that it is truly tainted. In the few times that this has happened to me, I have never been questioned, and have always been treated with apologies and the owner and staff going out of their way to reverse the situation. You are the customer, and if you believe the wine is bad, then it is bad. One note of caution, and I am just saying for those not having years of experience and training, you must know what that particular wine should taste like, within reason. There are some wines that have very particular nose and flavor to them that might not be pleasant to some, but expected to others, and the wine is fine.

I will conclude by saying that the best case of avoiding this is a process that I don’t see much of here in the United States, probably because of greed for the wine. I’m talking about the European wine culture, especially in the finer restaurants of Italy and France, where the wine Stewart will decant your wine, and pour a generous taste for him (or herself). It is their profession and their pleasure, for sure, to ensure that the expensive fine wine you purchased to accompany your dinner, is spectacular, and tainted in no way. Here in the U.S. I am sure that if a diner noticed an employee pouring and drinking from their expensive bottle of wine, serious things would happen, and not to pretty.